get down with your bad self
to misbehave, to party, to lose control of oneself and do things one shouldn't do, to get in touch with the rebellious part of one's personality
Example:
Look at her, she's been screwing every guy she meets! Yeah, she's gettin down with her bad self.
Look at her, she's been screwing every guy she meets! Yeah, she's gettin down with her bad self.